U.S. patent application number 13/582874 was filed with the patent office on 2012-12-20 for recyclable polyarylene sulfide and preparation method thereof.
This patent application is currently assigned to SK CHEMICALS CO., LTD.. Invention is credited to Il-Hoon Cha, Sung-Gi Kim.
Application Number | 20120322971 13/582874 |
Document ID | / |
Family ID | 44563960 |
Filed Date | 2012-12-20 |
United States Patent
Application |
20120322971 |
Kind Code |
A1 |
Kim; Sung-Gi ; et
al. |
December 20, 2012 |
RECYCLABLE POLYARYLENE SULFIDE AND PREPARATION METHOD THEREOF
Abstract
This disclosure relates to recyclable polyarylene sulfide that
may exhibit and maintain excellent mechanical properties,
particularly does not exhibit decrease in melt viscosity when it is
molten, and thus, exhibit little deterioration of mechanical
properties, and a method for preparing the same. The polyarylene
sulfide has initial melt viscosity measured at 300.quadrature. of
300 to 6000 poise, and melt viscosity after heat treated and molten
at 300.quadrature., equal to or greater than the initial melt
viscosity
Inventors: |
Kim; Sung-Gi; (Gyeonggi-do,
KR) ; Cha; Il-Hoon; (Gyeonggi-do, KR) |
Assignee: |
SK CHEMICALS CO., LTD.
Gyeonggi-do
KR
|
Family ID: |
44563960 |
Appl. No.: |
13/582874 |
Filed: |
February 28, 2011 |
PCT Filed: |
February 28, 2011 |
PCT NO: |
PCT/KR2011/001391 |
371 Date: |
September 5, 2012 |
Current U.S.
Class: |
528/381 |
Current CPC
Class: |
C08J 5/18 20130101; C08J
2381/04 20130101; C08G 75/16 20130101; C08G 75/14 20130101; C08G
75/02 20130101 |
Class at
Publication: |
528/381 |
International
Class: |
C08G 75/14 20060101
C08G075/14 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 9, 2010 |
KR |
10-2010-0021005 |
Claims
1. Polyarylene sulfide having initial melt viscosity measured at
300.degree. C. of 300 to 6000 poise, and melt viscosity after heat
treated and molten at 300.degree. C., equal to or greater than the
initial melt viscosity.
2. The polyarylene sulfide according to claim 1, wherein melt
viscosity change rate as defined by the following Equation 1 is 0
to 20%: Melt viscosity change rate(%)=100(MV.sub.f/MV.sub.i-1)
[Equation 1] in the Equation 1, MV.sub.i denotes the initial melt
viscosity of polyarylene sulfide, and MV.sub.f is the melt
viscosity of polyarylene sulfide after heat treating the
polyarylene sulfide at 300.degree. C. and melting it.
3. The polyarylene sulfide according to claim 2, wherein the
MV.sub.f is melt viscosity measured under shear rate of 1 rad/s in
a plate-plate rheometer, 10 minutes after heat treating the
polyarylene sulfide under inert gas atmosphere at 300.degree. C.
for 3 minutes to melt it.
4. The polyarylene sulfide according to claim 1, wherein the
polyarylene sulfide has number average molecular weight of 3,000 to
1,000,000.
5. The polyarylene sulfide according to claim 4, wherein the
polyarylene sulfide has number average molecular weight of 3,000 to
50,000.
6. The polyarylene sulfide according to claim 1, wherein the
polyarylene sulfide has a dispersion degree of 2.0 to 4.0 as
defined by the ratio of weight average molecular weight to number
average molecular weight.
7. The polyarylene sulfide according to claim 1, wherein the
polyarylene sulfide has a melting point of 265 to 320.degree.
C.
8. The polyarylene sulfide according to claim 1, wherein the
initial tensile strength of compounded resin including the
polyarylene sulfide and 40 wt % glass is 1000 kgf/cm.sup.2 or more,
as measured according to ASTM D638, and the tensile strength of the
compounded resin including polyarylene sulfide after passing an
extruder 4 times and 40 wt % glass is equal to or greater than the
initial tensile strength.
9. The polyarylene sulfide according to claim 1, wherein the
polyarylene sulfide has iodine content of 0.8 wt % or less.
10. A method for preparing the polyarylene sulfide of claim 1,
comprising polymerization reaction of reactants including diiodide
aromatic compounds, sulfur compounds, and based on 100 parts by
weight of the diiodide aromatic compounds, 0.05 to 10 parts by
weight of a polymerization terminator.
11. The method according to claim 10, wherein the diiodide aromatic
compounds are included in the reactants in the content of 0.9 moles
or more based on the sulfur compounds.
12. The method according to claim 10, wherein the polymerization
terminator is at least one selected from the group consisting of
diphenyl suldife, diphenyl ether, diphenyl, benzophenone,
monoiodoaryl compounds, benzothiazole, benzothiazolesulfenamide,
thiuram, dithiocarbamate and diphenyl disulfide.
13. The method according to claim 10, wherein the diiodide aromatic
compound is at least one selected from the group consisting of
diiodobenzene, diiodonaphthalene, diiodobiphenyl, diiodobisphenol,
and diiodobenzophenone.
14. The method according to claim 10, wherein the polymerization
reaction is conducted for 1 to 30 hours while increasing
temperature and decreasing pressure under the initial reaction
conditions of temperature of 180 to 250.degree. C. and pressure of
50 to 450 torr to the final temperature of 270 to 350.degree. C.
and the final pressure of 0.001 to 20 torr.
15. The method according to claim 10, further comprising melt
mixing the reactants including the diiodide aromatic compounds, the
sulfur compounds, and the polymerization terminator, before the
polymerization reaction.
16. The method according to claim 10, wherein the polymerization
reaction is progressed in the presence of a nitrobenzene-based
catalyst.
17. A molded product including the polyarylene sulfide according to
claim 1.
18. The molded product according to claim 17, wherein the molded
product is in the form of a film, a sheet or fiber.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to recyclable polyarylene
sulfide that may exhibit and maintain excellent mechanical
properties, does not exhibit decrease in melt viscosity when it is
molten, and thus, exhibit little deterioration of mechanical
properties, and a method for preparing the same.
BACKGROUND OF THE INVENTION
[0002] Currently, polyarylene sulfide is representative engineering
plastic, and is in great demand for high temperature and corrosive
environment and electronic products due to high heat resistance,
chemical resistance, flame resistance, and electric insulation. The
major uses include computer accessories, automobile accessories,
coating of the part contacting corrosive chemical materials, and
industrial chemical resistant fiber, and the like.
[0003] Presently, polyphenylene sulfide (PPS) is the only
commercially available polyarylene sulfide. According to the
current commercial production process of PPS, p-dichlorobenzene
(pDCB) and sodium sulfide are used as raw materials and reacted in
a polar organic solvent such as N-methyl pyrrolidone, and the like.
This method is known as a Macallum process, and the basic process
is disclosed in U.S. Pat. Nos. 2,513,188 and 2,583,941, wherein
some usable polar solvents are suggested, but N-methylpyrrolidone
is currently most commonly used. This process uses dichloro
aromatic compounds as raw material, and sodium chloride (NaCl) is
generated as a by-product.
[0004] The polyphenylene sulfide obtained in the Macallum process
includes residues such as sodium sulfide and organic solvent such
as N-methylpyrrolidone, and the like to some degree. Due to the
existence of the residues, decomposition may occur during use of
the polyphenylene sulfide, and particularly, if it is
melt-processed for recycling, decomposition of polyphenylene
sulfide by resides may occur more significantly.
[0005] Accordingly, deterioration of mechanical properties
according to use of polyphenylene sulfide after polymerization is
often observed, and if it is molten and molded for recycling of the
resin, mechanical properties may be further deteriorated, and thus,
there is significant limitations in recycling of expensive
polyphenylene sulfide.
SUMMARY OF THE INVENTION
[0006] The present invention provides polyarylene sulfide that may
exhibit and maintain excellent mechanical properties, and
particularly, exhibit little deterioration of mechanical properties
when it is molten, and thus, is recyclable.
[0007] Further, the present invention provides a method for
preparing the polyarylene sulfide.
[0008] The present invention also provides a molded product
including the polyarylene sulfide.
[0009] The present invention provides polyarylene sulfide having
initial melt viscosity measured at 300.quadrature. of 300 to 6000
poise, and melt viscosity after treat treated at 300.quadrature.
and molten, equal to or greater than the initial melt
viscosity.
[0010] The present invention also provides a method for preparing
the polyarylene sulfide, including polymerization reaction of
reactants including diiodide aromatic compounds, sulfur compounds,
and based on 100 parts by weight of the diiodide aromatic
compounds, 0.05 to 10 parts by weight of a polymerization
terminator.
[0011] The present invention also provides a molded product
including the polyarylene sulfide.
DETAILED DESCRIPTION OF THE INVENTION
[0012] Hereinafter, polyarylene sulfide according to one embodiment
and preparation method thereof, and the like will be explained in
detail.
[0013] During repeated studies on polyarylene sulfide that may
exhibit and maintain excellent mechanical properties, and even
after melt processed for recycling, has equal or more excellent
properties compared to immediately after polymerization, the
inventors completed the invention.
[0014] The inventors confirmed that polyarylene sulfide which has
equal or greater melt viscosity compared to initial melt viscosity
before heat treatment, even when it is heat treated at
300.quadrature. and molten, may be prepared according to the
following preparation method. Such melt viscosity change property
is novel property distinguished from the melt viscosity change
property of the polyarylene sulfide obtained by the existing
Macallum process.
[0015] It was also confirmed that the polyarylene sulfide having
the above melt viscosity change property has relatively high melt
viscosity, specifically maximum melt viscosity of 6,000 poise, and
thus, it may exhibit excellent mechanical properties. Particularly,
as the results of experiments, it was confirmed that as the
polyarylene sulfide may maintain or increase melt viscosity even
after it is molten at 300.quadrature., mechanical properties may
not be deteriorated during the use of products including the
polyarylene sulfide, and excellent mechanical properties before
molding may be maintained even when it is melt processed and
remolded for recycling.
[0016] Therefore, since the polyarylene sulfide may exhibit and
maintain excellent mechanical properties, and exhibit little
deterioration of mechanical properties even after remolten, it may
be usefully applied in the industrial field of preparing and
recycling polyarylene sulfide.
[0017] Meanwhile, the recyclable polyarylene sulfide according to
one embodiment of the invention as explained above has initial melt
viscosity measured at 300.quadrature. of 300 to 6000 poise, and
melt viscosity after heat treated and molten at 300.quadrature.,
equal to or greater than the initial melt viscosity.
[0018] As explained above, the polyarylene sulfide has excellent
thermal and mechanical properties basically exhibited during
polymerization, and simultaneously, even after remolten for
recycling, it has equal or more excellent mechanical property
values compared to immediately before polymerization.
[0019] As used herein, `initial melt viscosity` refers to melt
viscosity `immediately after polymerization` or melt viscosity
after polymerization `before it is molten to measure melt viscosity
change rate at 300.quadrature.`.
[0020] The polyarylene sulfide may preferably have melt viscosity
change rate of 0 to 20%, as defined by the following Equation
1.
Melt viscosity change rate(%)=100(MV.sub.f/MV.sub.i-1) [Equation
1]
[0021] In the Equation 1, MV, denotes the initial melt viscosity of
polyarylene sulfide, and MV, is the melt viscosity of polyarylene
sulfide after heat treating the polyarylene sulfide at
300.quadrature. and melting it.
[0022] If polyarylene sulfide has melt viscosity change rate after
heat treatment at a specific temperature in the above range, it may
not exhibit decrease in melt viscosity even after it is remolten,
and exhibit equal or more excellent mechanical properties compared
to before it is molten, and thus, it may be used without
deterioration of mechanical properties even after recycling.
[0023] The MV.sub.f may be defined as melt viscosity measured under
shear rate of 1 rad/s in a plate-plate rheometer, 10 minutes after
heat treating the polyarylene sulfide under inert gas atmosphere at
300.quadrature. for 3 minutes to melt it. If inert gas is used to
measure the melt viscosity change rate, nitrogen gas or argon gas,
and the like may be used as the inert gas, and preferably, readily
available nitrogen gas may be used.
[0024] And, the polyarylene sulfide may preferably have initial
melt viscosity of 300 to 6,000 poise, more preferably 500 to 4,000
poise, most preferably 600 to 2500 poise.
[0025] And, the polyarylene sulfide may have number average
molecular weight of 3,000 to 1,000,000, preferably 3,000 to
500,000, more preferably 3,000 to 50,000. And, the polyarylene
sulfide may have relatively uniform dispersion degree of 2.0 to
4.0, preferably 2.2 to 3.8, as defined by the ratio of weight
average molecular weight to number average molecular weight
(Mw/Mn).
[0026] The polyarylene sulfide having the above number average
molecular weight and/or dispersion degree may be manufactured into
various products according to the molecular weight or melt
viscosity.
[0027] Meanwhile, the polyarylene sulfide according to the above
embodiments exhibits excellent thermal stability, and specifically,
it has melting point (Tm) of 265 to 320.quadrature., preferably 268
to 290.quadrature., more preferably 270 to 285.quadrature.. By
securing Tm in the high range, the polyarylene sulfide may exhibit
excellent performances including high strength and improved heat
resistance, and the like, when applied to engineering plastic.
[0028] And, the polyarylene sulfide according to the above
embodiments exhibits excellent mechanical properties, and
simultaneously, it does not substantially exhibit deterioration of
mechanical properties even after it is remolten and/or
reinjected.
[0029] Specifically, the polyarylene sulfide according to one
embodiment may exhibit excellent mechanical properties, and
particularly, the initial tensile strength of compounded resin
including the polyarylene sulfide and 40 wt % glass is 1000
kgf/cm.sup.2 or more, as measured according to ASTM D638.
[0030] Furthermore, the tensile strength of the compounded resin
including the polyarylene sulfide that is 4 times extruded (namely,
passing an extruder 4 times) and 40 wt % glass may be equal to or
greater than the initial tensile strength, as measured according to
ASTM D638. Thereby, even if the polyarylene sulfide according to
one embodiment is recycled, mechanical properties may not be
deteriorated. Thus, the polyarylene sulfide may be preferably used
to mold engineering plastic requiring high strength, and the
like.
[0031] And, the polyarylene sulfide may have iodine content less
than 0.8 wt %. The iodine content may be quantified by measuring
with ion chromatograph (IC).
[0032] Since the polyarylene sulfide includes residual iodines
partly at the end group of the polymer even after polymerization,
due to continued polymerization reaction of residual iodines in the
polymerized polymer and unreacted sulfur, it may exhibit melt
viscosity measured after it is remolten, equal to or higher than
the initial melt viscosity.
[0033] According to another embodiment, there is provided a method
for preparing the above explained polyarylene sulfide including
polymerization reaction of reactants including diiodide aromatic
compounds, sulfur compounds, and based on 100 parts by weight of
the diiodide aromatic compounds, 0.05 to 10 parts by weight of a
polymerization terminator.
[0034] The polymerization terminator and the sulfur compounds may
be included in the initial reactants and the polymerization
reaction may be progressed, however, a part of the sulfur compounds
in the reactants may be introduced at a specific time elapsed after
the polymerization reaction is initiated. By dividedly introducing
a part of the sulfur compounds during the polymerization reaction,
polyarylene sulfide according to one embodiment that does not
exhibit deterioration of mechanical properties may be prepared. If
a part of the sulfur compounds are dividedly introduced during the
polymerization reaction, the content of the dividedly introduced
sulfur compounds is not limited, but to optimize the properties of
the finally prepared polyarylene sulfide, it may be 0.1 to 20 parts
by weight, preferably 1 to 10 parts by weight, more preferably 1 to
7 parts by weight, based on 100 parts by weight of the sulfur
compounds included in the initial reactants.
[0035] Furthermore, according to the above preparation method,
polyarylene sulfide may be prepared without using an organic
solvent or sodium sulfide. Thus, residues that may cause
decomposition of resin do not substantially exist in the finally
prepared polyarylene sulfide, and thus, there is little concern of
deterioration of mechanical properties during use as a product.
And, even if it is molt and molded for recycling, it may exhibit
equal or more excellent mechanical properties compared to before
recycling.
[0036] In the polyarylene sulfide obtained by the preparation
method according to the above explained embodiment, iodines remains
partly at the end of the main chain, and particularly, if an
appropriate ratio of the polymerization terminator is added to the
reactants and the polymerization reaction is progressed, an
appropriate amount of residual iodines may be included partly at
the end of the main chain of the polymerized polyarylene sulfide.
Thus, since the speed of additional polymerization reaction between
the residual iodines and unreacted sulfurs in the polyarylene
sulfide is higher than the speed of polyarylene sulfide
decomposition by unreacted residues in the polyarylene sulfide,
polyarylene sulfide having the above explained melt viscosity
change rate property may be prepared.
[0037] Meanwhile, the content range of the polymerization
terminator is not limited as long as it is within the above range,
but more preferably, 0.1 to 10 parts by weight of the
polymerization terminator may be included based on 100 parts by
weight of the diiodide aromatic compounds. As such, an appropriate
amount of residual iodines may be included at the end of the main
chain of the finally produced polyarylene resin by controlling the
content of the polymerization terminator in the reactants, and
thereby, polyarylene sulfide having melt viscosity after it is
remolten, equal to or greater than the initial melt viscosity, may
be obtained.
[0038] The polymerization terminator is not specifically limited as
long as it may remove iodine groups included in the polymerized
polymer to terminate polymerization, but it may be at least one
preferably selected from the group consisting of diphenyl ether,
diphenyl, benzophenone, diphenyl suldife, monoiodoaryl compounds,
benzothiazole, benzothiazolesulfenamide, thiuram, dithiocarbamate
and diphenylsulfide. More preferably, it may be at least one
selected from the group consisting of iodobiphenyl, iodophenol,
iodoaniline, iodobenzophenone, 2-mercaptobenzothiazole,
2,2'-dithiobisbenzothiazole,
N-cyclohexylbenzothiazole-2-sulfenamide,
2-morpholinothiobenzothiazole,
N,N-dicyclohexylbenzothiazole-2-sulfenamide, tetramethylthiuram
monosulfide, tetramethylthiuram disulfide, zinc
dimethyldithiocarbamate, zinc diethyldithiocarbamate,
dibenzothiazyl disulfide, and diphenyl disulfide.
[0039] Still more preferably, it may be dibenzothiazole disulfide,
diphenyl suldife, diphenyl ether, or biphenyl, wherein functional
groups between phenyls function as an electron donor, thus
exhibiting more higher reactivity of polymerization reaction.
[0040] Meanwhile, the diiodide aromatic compound that may be used
in the polymerization reaction of the polyarylene sulfide may be at
least one selected from the group consisting of diiodobenzene
(DIB), diiodonaphthalene, diiodobiphenyl, diiodobisphenol, and
diiodobenzophenone, but are not limited thereto, and diiodide
aromatic compounds wherein an alkyl group or a sulfone group, and
the like is additionally bonded as a substituent group, or
heteroatom such as oxygen or nitrogen, and the like is contained in
the aryl compound may be also used. The diiodide aromatic compounds
may be in the form of various isomers according to the bonding
position of iodine atoms, and compounds such as pDIB,
2,6-diiodonaphthalene, or p,p'-diiodobiphenyl, wherein iodines are
symmetrically bonded at both ends at the farthest distance may be
most preferable.
[0041] Furthermore, sulfur compounds that may be used are not
limited. Commonly, sulfur exists as cyclooctasulfur (S8) at room
temperature, but any commercially available solid state sulfur may
also be used.
[0042] And, the diiodide aromatic compounds may be introduced in
the content of 0.9 moles or more, based on the solid sulfur
compounds. And, the sulfur compounds may be preferably included in
the content of 15 to 30 wt %, based on the weight of the
polyarylene sulfide prepared by reacting the diiodide aromatic
compounds and the sulfur compounds. If the sulfur is added in the
above range, polyarylene sulfide having increased heat resistance
and chemical resistance, and simultaneously having excellent
properties including mechanical properties, and the like may be
synthesized.
[0043] Meanwhile, the polymerization reaction may be progressed
under conditions that may initiate a polymerization of reactants
including diiodide aromatic compounds, sulfur compounds and
polymerization terminator. Preferably, the polymerization may be
progressed under temperature-increasing and pressure-reducing
conditions, and in this case, the polymerization reaction may be
progressed for 1 to 30 hours while increasing temperature and
reducing pressure under the initial reaction conditions of
temperature of 180 to 250.quadrature. and the pressure of 50 to 450
torr to the final temperature of 270 to 350.quadrature. and the
final pressure of 0.001 to 20 torr.
[0044] If the polymerization reaction is progressed under
temperature increasing and pressure reducing conditions,
polyarylene sulfide may exhibit excellent thermal stability, and it
may exhibit melt viscosity change rate of 0% or more even after it
is remolten for recycling, and thus, exhibit equal or more
excellent mechanical properties compared to before recycling.
[0045] Meanwhile, the method for preparing polyarylene sulfide
according to the above explained embodiment may further include a
step of melt mixing reactants including diiodide aromatic
compounds, sulfur compounds and polymerization terminator before
the polymerization reaction step. The above explained
polymerization reaction is progressed as a melt polymerization that
is progressed in the absence of an organic solvent, and to progress
the melt polymerization, reactants including diiodide aromatic
compounds may be previously melt mixed, and then, the
polymerization reaction may be progressed.
[0046] The melt mixing conditions are not limited as long as it may
melt mix all the reactants, but preferably, the melt mixing may be
progressed at a temperature of 130 to 200.quadrature..
[0047] By conducting melt mixing before polymerization, melt
polymerization may be more easily achieved.
[0048] Meanwhile, the polymerization reaction may be progressed in
the presence of a nitrobenzene-based catalyst. And, if a melt
mixing step is conducted before the polymerization reaction, the
catalyst may be added in the melt mixing step. I was found out that
if polymerization reaction is progressed in the presence of the
nitrobenzene-based catalyst, polyarylene sulfide having higher
melting point than the polymerization in the absence of a catalyst
may be prepared. If polyarylene sulfide has low melting point,
there is a problem in heat resistance of a product, and thus, to
prepared polyarylene sulfide requiring heat resistance, the
polymerization reaction may be progressed in the presence of a
nitrobenzene-based catalyst. The nitrobenzene-based catalyst may
include 1,3-diiodo-4-nitrobenzene, or 1-iodo-4-nitrobenzene, and
the like, but is not limited thereto.
[0049] The polyarylene sulfide prepared according to the above
preparation method has initial melt viscosity measured at
300.quadrature. of 300 to 6000 poise, more preferably 500 to 4,000
poise, most preferably 600 to 2500 poise, and melt viscosity after
it is heat treated and molten at 300.quadrature., equal to or
greater than the initial melt viscosity.
[0050] And, the polyarylene sulfide prepared according to the above
preparation method has melt viscosity change rate of 0 to 20%, as
defined by the following Equation 1:
Melt viscosity change rate (%)=100(MV.sub.f/MV.sub.i-1) [Equation
1]
[0051] In the Equation 1, MV.sub.i denotes the initial melt
viscosity of polyarylene sulfide, and MV.sub.i is the melt
viscosity of polyarylene sulfide after heat treating the
polyarylene sulfide at 300.quadrature. to melt it.
[0052] The MV.sub.f may be defined as melt viscosity measured under
shear rate of 1 rad/s in a plate-plate rheometer, 10 minutes after
heat treating the polyarylene sulfide under inert gas atmosphere at
300.quadrature. for 3 minutes to melt it.
[0053] And, the number average molecular weight, dispersion degree
defined by weight average molecular weight to number average
molecular weight, number average molecular weight, melting point,
and the like of the polyarylene sulfide prepared according to the
above preparation method are as explained in the embodiments of
polyarylene sulfide.
[0054] According to yet another embodiment, there is provided a
molded product including the polyarylene sulfide. The molded
product may be in the form of a film, a sheet or fiber, and the
like.
[0055] The molded product may be obtained by injection molding,
extrusion molding, blow molding of the polyarylene sulfide. In the
case of injection molding, mold temperature may be preferably
30.quadrature. or more, more preferably 60.quadrature. or more,
still more preferably 80.quadrature. or more in terms of
crystallization, and it may be preferably 150.quadrature. or less,
more preferably 140.quadrature. or less, still more preferably
130.quadrature. or less in terms of modification of test piece.
And, the product may be used as electric and electronic parts,
construction element, automobile parts, machine parts or daily
necessities, and the like. And the injection molded product may be
compounded with glass fiber and then molded. The content of the
glass fiber is not limited, but to maintain excellent properties of
the polyarylene sulfide and simultaneously increase mechanical
strength including tensile strength, and the like, it may be
included in the content of 10 to 50 wt %, preferably 35 to 45 wt
%.
[0056] The molded product may be made into various films or sheets
including undrawn, uniaxially drawn, biaxially drawn film, sheet,
and the like. If the molded product is fiber, it may be made into
various fibers including undrawn, drawn, ultra-drawn fiber, and the
like, which may be used as woven fabrics, knitting, non-woven
fabrics (spun bond, melt blow, staple), rope, net, and the
like.
[0057] The polyarylene sulfide of the present invention may exhibit
and maintain excellent mechanical properties, particularly exhibit
little deterioration of mechanical properties even when it is
molten, and thus, it may be usefully applied in the industrial
field of preparing and recycling polyarylene sulfide.
[0058] Hereinafter, the present invention will be explained
referring to the following Examples and Comparative Examples, but
the scope of the invention is not limited thereto.
COMPARATIVE EXAMPLE
Polymerization of Polyarylene Sulfide
1. Polyarylene Sulfide of Comparative Example 1
[0059] 0205P4 grade polyarylene sulfide (Ticona Company) was
prepared. The polymer had melt viscosity (MV) of 700 poise, melting
point TM of 282.quadrature., and melt viscosity change rate of
-12%/10 min, as measured under shear rate of 1 rad/s in a
plate-plate rheometer, after heat treating the polyarylene sulfide
under inert gas atmosphere at 300.quadrature. for 3 minutes to melt
it.
2. Polyarylene Sulfide of Comparative Example 2
[0060] Polyarylene sulfide of hb grade (Deyang Company) was
prepared, which is polymerized grade polyarylene sulfide
polymerized by the same method as Comparative Example 1 except that
MV is different.
[0061] The polymer had MV 2000 poise, Tm 280.quadrature., and melt
viscosity change rate of -9%/10 min, as measured under shear rate
of 1 rad/s in a plate-plate rheometer, after heat treating the
polyarylene sulfide under inert gas atmosphere at 300.quadrature.
for 3 minutes to melt it.
3. Polyarylene Sulfide of Comparative Example 3
[0062] Polyarylene sulfide of Ryton P6 grade (Chevron Philips
Company) was prepared, which is polymerized grade polyarylene
sulfide polymeized by the same method as Comparative Example 1
except that MV is different.
[0063] The polymer had MV 1100 poise, Tm 281.quadrature., and melt
viscosity change rate of -23%/10 min, as measured under shear rate
of 1 rad/s in a plate-plate rheometer, after heat treating the
polyarylene sulfide under inert gas atmosphere at 300.quadrature.
for 3 minutes to melt it.
EXAMPLE
Polymerization of Polyarylene Sulfide
1. Polymerization of Polyarylene Sulfide of Example 1
[0064] Reactants including 4000 g of para diiodobenzene, 10 g of
polymerization terminator, 345 g of sulfur, and 15 g of
1,3-diiodo-4-nitrobenzene were melt mixed at 180.quadrature.. A
polymerization reaction was progressed while increasing the
temperature of the mixture from 180.quadrature. to 340.quadrature.,
and reducing the pressure from atmospheric pressure to 10 torr. 5
hours after the polymerization was initiated, 5 g of sulfur was
additionally introduced, and polymerization was progressed for
additional 3 hours to obtain polymer.
[0065] The produced polymer had MV 700 poise, Tm 280.quadrature.,
and melt viscosity change rate of +3%/10 min, as measured under
shear rate of 1 rad/s in a plate-plate rheometer, after heat
treating the polyarylene sulfide under inert gas atmosphere at
300.quadrature. for 3 minutes to melt it.
2. Polymerization of Polyarylene Sulfide of Example 2
[0066] Reactants including 4000 g of para diiodobenzene, 12 g of
polymerization terminator, 350 g of sulfur, and 15 g of
1,3-diiodo-4-nitrobenzene were melt mixed at 180.quadrature.. A
polymerization reaction was progressed while increasing the
temperature of the mixture from 180.quadrature. to 340.quadrature.,
and reducing the pressure from atmospheric pressure to 10 torr. 5
hours after the polymerization was initiated, 10 g of sulfur was
additionally introduced, and polymerization was progressed for
additional 4 hours to obtain polymer.
[0067] The produced polymer had MV 1100 poise, Tm 278.quadrature.,
and melt viscosity change rate of +4%/10 min, as measured under
shear rate of 1 rad/s in a plate-plate rheometer, after heat
treating the polyarylene sulfide under inert gas atmosphere at
300.quadrature. for 3 minutes to melt it.
3. Polymerization of Polyarylene Sulfide of Example 3
[0068] Reactants including 4000 g of para diiodobenzene, 15 g of
polymerization terminator, 355 g of sulfur, and 15 g of
1,3-diiodo-4-nitrobenzene were melt mixed at 180.quadrature.. A
polymerization reaction was progressed while increasing the
temperature of the mixture from 180.quadrature. to 340.quadrature.,
and reducing the pressure from atmospheric pressure to 10 torr. 5
hours after the polymerization was initiated, 15 g of sulfur was
additionally introduced, and polymerization was progressed for
additional 5 hours to obtain polymer.
[0069] The produced polymer had MV 2000 poise, Tm 278.quadrature.,
and melt viscosity change rate of +7%/10 min, as measured under
shear rate of 1 rad/s in a plate-plate rheometer, after heat
treating the polyarylene sulfide under inert gas atmosphere at
300.quadrature. for 3 minutes to melt it.
4. Polymerization of Polyarylene Sulfide of Example 4
[0070] Reactants including 4000 g of para diiodobenzene, 17 g of
polymerization terminator, 358 g of sulfur, and 15 g of
1,3-diiodo-4-nitrobenzene were melt mixed at 180.quadrature.. A
polymerization reaction was progressed while increasing the
temperature of the mixture from 180.quadrature. to 340.quadrature.,
and reducing the pressure from atmospheric pressure to 10 torr. 5
hours after the polymerization was initiated, 18 g of sulfur was
additionally introduced, and polymerization was progressed for
additional 8 hours to obtain polymer.
[0071] The produced polymer had MV 2000 poise, Tm 275.quadrature.,
and melt viscosity change rate of +10%/10 min, as measured under
shear rate of 1 rad/s in a plate-plate rheometer, after heat
treating the polyarylene sulfide under inert gas atmosphere at
300.quadrature. for 3 minutes to melt it.
5. Polymerization of Polyarylene Sulfide of Example 5
[0072] Reactants including 4000 g of para diiodobenzene, 12 g of
polymerization terminator, 355 g of sulfur, and 15 g of
1,3-diiodo-4-nitrobenzene were melt mixed at 180.quadrature.. A
polymerization reaction was progressed while increasing the
temperature of the mixture from 180.quadrature. to 340.quadrature.,
and reducing the pressure from atmospheric pressure to 10 torr. 5
hours after the polymerization was initiated, 10 g of sulfur was
additionally introduced, and polymerization was progressed for
additional 5 hours to obtain polymer.
[0073] The produced polymer had MV 1200 poise, Tm 279.quadrature.,
and melt viscosity change rate of +2%/10 min, as measured under
shear rate of 1 rad/s in a plate-plate rheometer, after heat
treating the polyarylene sulfide under inert gas atmosphere at
300.quadrature. for 3 minutes to melt it.
[0074] The reactants and the added amounts of the polymerization
reactions of Comparative Examples and Examples are shown in the
following Table 1, and the property values of the resins
polymerized by different methods of Examples and Comparative
Examples are measured according to the following Experimental
Example and shown in the following Table 2.
[Preparation of Melt Processed Products of Polyarylene Sulfide of
Examples and Comparative Examples]
[0075] 40 wt % of glass fiber, 0.3 wt % of lubricant, 0.2 wt % of
oxidation stabilizer, and remaining content of the polyarylene
sulfide resin polymerized according to Comparative Examples 1 to 3
and Examples 1 to 5 were introduced into a twin screw extruder, and
compounded (HAAKE Company, PolyLab System, 340.quadrature.), and
then, dried at 150.quadrature. for 2 hours, and, injection mold
temperature was fixed at 140.quadrature., and then, tensile
specimen was injected with an injector (Boy Company, 12M,
320.degree.), and tensile strength of the compounded specimen was
measured.
[0076] And, 40 wt % of glass fiber, 0.3 wt % of lubricant, 0.2 wt %
of oxidation stabilizer, and remaining content of the polyarylene
sulfide resin polymerized according to Comparative Examples 1 to 3
and Examples 1 to 5 after passing a twin screw extruder 4 times,
(HAAKE Company, PolyLab System, 315.quadrature.) were mixed to
prepare compounded resin.
[0077] The tensile strengths of the resin immediately after
polymerization and the resin after passing an extruder 4 times of
Examples and Comparative Examples were measured and shown in the
following Table 3.
EXPERIMENTAL EXAMPLE
Measurement of Polyarylene Sulfide of Comparative Examples and
Examples
1. Analysis of Melt Viscosity
[0078] For the property analysis of the polymers synthesized
according to Comparative Examples and Examples, melt viscosity was
measured at 300.quadrature. with a rotating disk viscometer. To
measure by Frequency sweep method, angular frequency was measured
from 0.6 to 500 rad/s, and the viscosity at 1.0 rad/s was defined
as melt viscosity.
2. Measurement of Melting Point (Tm)
[0079] Melting point was measured using Differential Scanning
calorimeter (DSC) while increasing temperature from 30.quadrature.
to 320.quadrature. at a speed of 10.quadrature./min, cooling to
30.quadrature., and then, increasing temperature again from
30.quadrature. to 320.quadrature. at a speed of
10.quadrature./min.
3. Measurement of Melt Viscosity Change Rate
[0080] The polymer samples polymerized according to Examples and
Comparative Examples were molten at 300.quadrature. for 3 minutes
under nitrogen atmosphere, and then, melt viscosity was measured at
1 second intervals under shear rate of 1 rad/s in a plate-plate
rheometer. The melt viscosity change rate was measured based on the
melt viscosity measured after 10 minutes. The change rate is
expressed as the following Equation 1.
Melt viscosity change rate(%)=100(MV.sub.f/MV.sub.i-1) [Equation
1]
[0081] In the Equation 1, MV, denotes the initial melt viscosity of
polyarylene sulfide, and MV, is the melt viscosity of polyarylene
sulfide after heat treating the polyarylene sulfide at
300.quadrature. to melt it.
4. Tensile Strength
[0082] Tensile strength was measured when a type I specimen was
pulled at a speed of 5 mm/min using UTM (Universal testing machine,
Dong-il Shimadzu Corp., AG-X 10 kN) according to the method
described in ASTM D638.
5. Measurement of Elongation
[0083] Elongation was measured when a type I specimen was pulled at
a speed of 5 mm/min using UTM (Universal testing machine, Dong-il
Shimadzu Corp., AG-X 10 kN) according to the method described in
ASTM D638. The used gauge length was 50 mm, and the elongation
means the stretched length of material at tensile test.
6. Analysis of Iodine Content in Polyarylene Sulfide
[0084] After grinding samples, a specific amount thereof was
combusted and ionized with absorbent such as pure water, and the
like, and then, the concentration of iodine ions was measured using
combustion ion chromatograph. As the combustion equipment, AQF-100
(Mitshubishi Company) was used, and as the IC equipment, ICS-2500
(DIONEX Company) was used.
TABLE-US-00001 TABLE 1 Preparation of polyarylene sulfide of
Comparative Examples Comparative 0205P4 grade (Ticona Company)
Example 1 Comparative hb grade (Deyang Company) Example 2
Comparative Ryton P6 grade (Chevron Philips Company) Example 3
Total Reactants of Examples Introduction polymerization
Polymerization Additionally time of reaction pDIB terminator**
Sulfur catalyst* introduced sulfur*** time (g) (g) (g) (g) sulfur
(g) (hr) (hr) Example 1 4000 10 345 15 5 5 8 Example 2 4000 12 350
15 10 5 9 Example 3 4000 15 355 15 15 5 10 Example 4 4000 17 358 15
18 5 13 Example 5 4000 12 355 15 10 5 10 (comment) *As the
catalyst, 1,3-diiodo-4-introbenzene is used. **As the
polymerization terminator, diphenyl disulfide is used. ***The
introduction time of additional S refers to the time elapsed after
the polymerization reaction is initiated.
TABLE-US-00002 TABLE 2 Properties of polyarylene sulfide MV.sub.f
M.V. change Tm (.quadrature.) MV.sub.i (Poise) (Poise) rate (%)
Comparative Example 1 282 700 616 -12 Comparative Example 2 280
2000 1820 -9 Comparative Example 3 281 1100 847 -23 Example 1 280
700 721 3 Example 2 278 1100 1144 4 Example 3 278 2000 2140 7
Example 4 275 2000 2200 10 Example 5 279 1200 1224 2
TABLE-US-00003 TABLE 3 Immediately after polymerization After
passing extruder 4 times Compounding Compounding tensile Iodine
tensile Iodine strength elongation content strength Elongation
content (kgf/cm.sup.2) (%) (wt %) (kgf/cm.sup.2) (%) (wt %)
Comparative 1700 1.9 0 1650 1.8 0 Example 1 Comparative 1400 1.8 0
1310 1.6 0 Example 2 Comparative 1500 1.3 0 1360 1.2 0 Example 3
Example 1 1520 1.7 0.6 1590 1.7 0.6 Example 2 1570 1.6 0.4 1620 1.7
0.4 Example 3 1630 1.8 0.3 1670 1.9 0.3 Example 4 1580 1.5 0.2 1640
1.6 0.2 Example 5 1600 1.7 0.4 1670 1.8 0.4
[0085] As shown in the Table 2, the products of Comparative Example
have minus melt viscosity change rate, while the products of
Examples 1 to 5 have plus melt viscosity change rate. Thus, as
shown in the Table 3, the products of Comparative Examples 1 to 3
have decreased tensile strength after passing the extruder 4 times,
while the products of Examples 1 to 5 have increased tensile
strength after passing the extruder 4 times, compared to
immediately after polymerization. There is not substantial
difference between iodine contents immediately after polymerization
and after passing the extruder 4 times, but the iodine content may
be decreased a little within measurement method error.
[0086] Meanwhile, from these results, it is expected that the
polyarylene sulfide of Examples may exhibit and maintain excellent
mechanical properties, particularly exhibit little deterioration of
mechanical properties, and thus, it may be usefully applied in the
industrial field of preparing and recycling polyarylene
sulfide.
* * * * *